Watch at about the 1:20 mark. There's a rear facing child back there getting hit on their side.
[ame="http://www.youtube.com/watch?v=C10hE5wrMVM"]Crash Test 2010 - 20** Suzuki Swift (Full Test) EuroNcap - YouTube[/ame]
For lack of a better term, it looks comfortable. Hardly as violent as the other occupants.
The backseat, with a properly installed and properly used restraint, is as safe as your child can get. Let's say 100%. You're talking about taking someone and if the wings do something, maybe making them 103% safe. Or in the center it may be as much as 130%. Would I try for the center? Sure. If it didn't work would I stress it? No, because my kids are still 100% safe. In fact, when my second was on her way I put my older daughter's Nautilus on the other side, put a True Fit behind me, and my younger daughter has ridden behind me since day one. Now I have a car with no center, so that choice is removed for me.
Wendy